<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="css/style.css">
</head>
<body>
<!--
  1. 不改变数字顺序
  2. 使用浮动
  3. 完成 123 的6种数字排列
-->
<div class="left">
 <div class="left">
     <div class="box right">1</div>
     <div class="box right">2</div>
 </div>

<div class="box right">3</div>
</div>

<div class="clear-fix">
   hello
</div>


</body>
</html>